User Manual

8-8 Beginning Programming
Backtrack Gap
This is the vertical distance that the dispensing head moves up after completion of a move.
At the end of a move, the dispensing head raises the Backtrack Gap, then moves the
Backtrack Length back over the line that was just dispensed. This encourages congealed
fluids to detach and distributes any excess fluid back across the line. The units are inches.
Backtrack Gap should be at least double the Dispense Gap.
Backtrack Length
This is the horizontal distance that the dispensing head moves back over the dispensed line
after raising up the Backtrack Gap distance. This encourages congealed fluids to detach and
distributes any excess fluid back across the line. The units are inches. Typically, 30 - 40 mils
(0.030 - 0.040 in) is sufficient.
Backtrack Speed
This is the speed that the dispensing head travels when moving along the Backtrack Length.
The units are inches/second. Typically, 2 in/sec is sufficient.
Retract Distance
This is a vertical distance that the dispensing head moves after the Backtrack Gap and
Backtrack Length dispensing commands have completed. Figure 8-2 shows the relationship
between Retract Distance, Backtrack Gap and Backtrack Length. The Retract Distance must
be within the Safe-Z Height defined in Initial Setup. The units are inches. Typically, 250
mils (0.250 inches) is sufficient.
Retract Speed
This is the speed of the dispensing head while moving the Retract Distance. The units are in
inches/second. Typically, 2 in/sec is sufficient.
Retract Acceleration
This is the parameter that controls how fast the dispensing head comes up to the Retract
Speed. You may need to set this high for small dispensing moves. The units are
inches/second
2
. Typically, 300 in/sec
2
is sufficient.
Figure 8-2
3. Click on OK to close the Line Parameters dialog box and return to the Programming
Window.
Backtrack Gap
Backtrack Length
Retract Distance